1. The problem statement, all variables and given/known data Two blocks have masses m1 and m2 and speeds v1 and v2. The objects slide directly toward each other along a frictionless horizontal surface and collide. After the collision, block m1 is at rest. Find the work done by the contact force on block m2 during the collision. 2. Relevant equations W = 1/2*m*v_f^2 - 1/2*m*v_i^2 m*v_1 + m*v_2 = m*v_1' + m*v_2' 3. The attempt at a solution m_1*v_1+m_2*v_2 = 0+m_2v_2' v_2' = (m_1*v_1+m_2*v_2)/m_2 W = 1/2*m_2*((m_1*v_1+m_2*v_2)/m_2)^2 - 1/2*m_2*v_2^2 What am I doing wrong?